<!DOCTYPE html>

<html>

  <head>

    <meta charset="utf-8">

    <title>jsScreenShots</title>

  </head>

  <body>

    <h1>qwsnqwascascascascascas</h1>

    <h2>q</h2>

    <h3>sdsdsv</h3>

    <h4>qwqwqwascacascas</h4>

    <h1>qwsnqwascascas</h1>

    <h2>q</h2>

    <h3>sdsdsv</h3>

    <h4>qwqwqw</h4>

  </body>

<script src="https://cdn.bootcss.com/jquery/3.2.1/jquery.min.js"></script>

<script src="https://cdn.bootcss.com/jcanvas/16.7.3/jcanvas.min.js"></script>

<script src="https://cdn.bootcss.com/html2canvas/0.5.0-beta4/html2canvas.min.js"></script>

<script src="screenshot.js"></script>

<script type="text/javascript">

  screenShot([16, 65], 27) // 开始快捷键设置为shift+a；退出键为ESC

</script>

</html>